Reaction clamp for conductors or the like



July 6, 1937. A. o. AUSTIN REACTION CLAMP FOR CONDUCTORS OR THE LIKE Filed Nov. 29, 1933 6 Sheets-Sham'I 1 INVENTOR x July 6, 1937. A. o. AUSTIN 2,086,150

REACTION CLAMP FOR CONDUCTORS OR THE LIKE Filed NOV. 29, 1933 6 Sheets-Shea?l 2 Fig. I3.

INVENTOR July 6, 193,7. A. o. AUSTIN REACTION CLAMP FOR CONDUCTORS OR THE LIKE Filed Nov. 29, 1933 6 Sheets-Sheet 3 Flg WIE W July 6, 1937. A. o. AUSTIN 2,086,150

REACTION CLAMP FOR CONDUCTORS OR THE LIKE Filed Nov. 29, 1953 6 Sheets-Sheet 4 v INVENTOR @Gang July 6,A 1937. A. o. AUSTIN v REACTION CLAMP FOR CONDUCTORS OR THE LIKE Filed Nov. 29, 1953 6 Sheets-Sheet 5 B ANGLE OF SAG 66 DEGRS OOO www@ O C O 6 A. 2

INVENTOR @Mb July 6, 1937. A. o. AUSTIN REACTION CLAMP FOR CONDUCTORS OR THE LIKE Filed Nov. 29, 1933 6 Sheets-Sheet 6 INVENTOR k r s @E cotan xyH] +(ycosec ARC: (2x/180)(1TR) (a cotanx) H ARC (2 x/lso)(1TR) Patented July 6, 1937 UNITED STTES .insane PATENT @FFCE Arthur G. Austin, near Barberton, Ohio Appiicatien November 29, 1933, Serial No. '700,270

i2 Ciaims.

This invention relates to clamps for holding the conductors of electrical transmission lines or other cables and more particularly conductors which require a large radius of curvature at the point of support or which are likely to ce damaged by vibration or power arcs.

One object of the invention is to provide a clamp which will automatically permit a wide range in the angle of sag.

A further object is to provide a construction which will permit travelling waves or oscillations with a minimum amount of displacement at the clamp.

A further object is to provide means whereby the grip of the clamp is controlled by tension and direction of the conductor.

A further object is to control the pressure between clamp seats and conductor.

A further object is to provide a construction which permits of the absorption or" the energy of vibration.

A further object is to provide a clamp which reduces the bending or exure. of the members composing the conductor due to vibration or change in angle of sag.

A further object is to provide a construction which will shield the conductor from power arcs.

A further object is to provide a construction which will permit high operating voltages without corona discharge.

A further object is to provide a construction which may be used to reduce or control the grip of the. conductor and relieve the insulators and supporting structure in case oi a broken conductor.

A further object is to provide a clamp which will be simple to manufacture and install and which will reduce the tendency of the conductor to be damaged by chang or fatigue due to vibrations or oscillations, or change in the angle of sag.

Other objects and advantages will appear from the following description.

The invention is exemplified in a combination and arrangement of parts shown in the accomo panying drawings and described in the following specification, and it is more particularly pointed out in the appended claims.

In the drawings:

Fig. l is an elevation of one form of the clamp.

Fig. 2 is an enlarged section on line 2-2 of Fig. l.

Fig. 3 is an enlarged section on line 3-3 of Fig. l.

Fig. 4 is an elevation showing another modiiication oi the clamp.

Fig. 5 is an enlarged section on line 5---5 of Fig. Ll.

Fig. 6 is an enlarged section on line G-E of Fig. fi.

Fig. 'l is an enlarged section on line l'--l of Fig. 4.

Fig. 8 is an elevation of another modification of the clamp.

Fig. 9 is an enlarged section on line 9-9 ci Fig. 8.

Fig. i() is an enlarged section on line ID--l of Fig. 8.

Fig. l1 is an elevation of another modification of the ciamp.

Fig. l2 is a plan of the clamp shown in Fig. ll.

Fig. i3 is an enlarged section on line |3--l3 of Fig. l1.

Fig. i4 is an enlarged section on line l4--I4 of Figs. li and l2.

Fig. i5 is another modification of the clamp.

Fig. 16 is an enlarged section on line iii-if@ of Figure i5.

Fig. 17 is an elevation of another modification oi the clamp.

Fig. 18 is an enlarged section on line lS-I of Fig. 17.

Fig. 1G is an enlarged section on line 9l9 of Fig. 1'7.

Fig. 2() is an enlarged section on line Eil-2S oi Fig. i7.

Fig. 2l is a fragmentary elevation of a modied form of clamping member.

Fig. 22 is an elevation oi another modiiication or the clamp.

Fig. 23 is an enlarged section on line i3-23 oi Fig. 22.

Fig. 24 is an enlarged section on line 24-24 oi Fig. 22.

Fig. 25 is an enlarged section on line 25-25 of Fig. 22.

Fig. 26 is another modication of the clamp.

Fig. 27 is an enlarged section on line 21-21 of Fig. 26.

Fig. 28 is an enlarged section on line 28-28 of Fig. 26.

Fig. 29 is an enlarged section on line 29-29 of Fig. 26.

Fig. 30 is an elevation of another modication of the clamp.

Fig. 3l is an enlarged section on line 3l-3l of Fig. 30.

Fig. 32 is a diagram oi conductor and clamp showing the general arrangement oi forces between clainp members and conductor, the arms being mounted on a yoke.

Fig. 33 is a diagram showing the resultant forces between conductor and clamp, the arms having a common point of rotation below the center line of the conductor.

Fig. 34 is a diagram showing the resultant forces between conductor and clamp, the arms having a common point of rotation above the center line of the conductor.

Fig. 35 is a. graph showing the eiect of lever arm ratio upon clamp friction.

Fig. 36 is a graph showing the effect of sag angle upon clamp friction for several different arm ratios.

37 is a side elevation of a clamp with the lever arms extending toward each other.

Fig. 38 is a side elevation of a clamp with articulated main seats.

Fig. S9 is an enlarged section on line 39-39 of Fig. 38.

Fig. 40 is an enlarged section on line 40--40 of Fig. 38.

Figs. 4l. and 42 are diagrammatic views illustrating the action of the invention.

In the electrical transmission of power there is tendency toward the use of higher operating voltages in order to effect greater economy or reliability of operation. The limitations due to regulation or stability particularly where the transmission frequencies are high and the distances are long make it necessary to use high operating voltages in order to reduce the effect of reactance. As the voltage is increased the amount of current required for the transmission oi a given amount of power is reduced, therefore it is frequently possible to use conductors of rather small cross section without incurring excessive resistance losses in the conductor. However, at the high operating voltages it is necessary that the conductor have a diameter sufficiently great that losses due to corona or brush discharge will be within economic limits.

In order to save the cost of material, conductors having hollow cores or lightened construction frequently are used. These conductors may be in the form of segmental tubes or have hollow strands or lightened cores constructed in various ways. Other types of conductors having large diameters may be composed of an outer conducting layer and a high strength core with or without a spacing layer between the two parts. High .vorking tensions in the conductor cable reduce the sag and the number of supports required. The large diameter and high working tension tend to increase the danger of damage to the conductor due to vibrations or oscillations caused by wind upon the conductor or to working loads which may cause high stresses localized at the point of support.

The best combinations of diameter, cross sec tion of material and working tensions for economical reasons may materially increase the danger of fatigue due to vibration or oscillation, or the flexing of the conductor at the point of support. The changes in the angle of sag or movement due to wind may cause a serious bending and fatigue of the material particularly where the diameter and elements of the conductor are large, or the material is such that the flexing or bending will cause fatigue and failure of the material.

As the diameter of the conductor is increased it is highly advisable that the radius of curvature at the suspension clamp be increased so that serious flexing or bending will not take place and lower the effective ultimate strength of the 0011-' ductor or shorten its economic life. It is advisable that the radius oi curvature should be sufliciently large so that any change in the effective radius of curvature due to vibration or change in the angle of sag will not cause overstressing and crystallization or fatigue in any part of the conductor.

It is possible to provide a large radius of curvature with the clamps ordinarily used having a curved seat of xed radius by making the seat long enough even where the angle of sag is considerable. However, where a clamp of this kind is used any decrease in the angle of sag due to low temperature or other causes will raise the conductor from the seat of the clamp at the point of entry. Should vibration take place under this condition the conductor will beat against the clamp, which may cause serious damage to the conductor or clamp. If the conductor touches the side wall of the clamp the movement will cause wear which may damage both conductor and clamp. In conductors of the lighter construction particularly those of hollow construction, the conductor may flatten slightly which will cause it to bear upon the side walls of the clamp even though clearance may have been provided for the normal cross section of conductor.

While the friction may tend to dampen out oscillations, the wear and damage to the conductor and clamp is likely to be serious. It is therefore advisable that the relation between the conductor and clamp seat be maintained so that there will be no serious movement between them due to vibration or temperature changes which will cause wear and damage to the conductor.

While contact between conductor and clamp seat may be maintained by providing a clamping member at the outer end of the clamp seat, where this is done any reduction or change in the angle of sag during construction or operation will tend to cause the conductor to bend at the point of entrance.

Heavy loading of the conductor or pressure and friction between the strands may cause a reduction in diameter so that the grip of clamping bolts may be reduced or entirely released. This will permit vibration and pounding between the conductor and clamp. A heavy grip occasioned by clamping members at the point of entry may cause a deformation and weakening of the component parts of the conductor. The use of a grip member at the point of entry of the conductor to the clamp seat is therefore open to serious objections. Conductors having hollow cores, light cross section `or those having a soit outer layer are easily damaged by clamping too tightly. As the conductor tends to decrease in diameter with an increase in tension it is necessary to provide a high gripping pressure where bolts are used in order that there will be no looseness between the conductor and seat due to tension in the conductor which will permit damage due to vibration. It is diiiicult to provide sufficient resiliency in the grip members to .insure tightness over the range of working conditions and it is frequently very diiiicult to prevent U bolts or J bolts from loosening due to vibration.. Where the bolts loosen due to vibration or the corrosion of lock washers or bearing parts, the looseness may readily eaus damage after a period of time.

For the above reasons it is highly advisable that a clamp construction be provided which will permit of a long radius of curvature so that the conductor or component parts will not be seriously bent or flexed under operating conditions. It is highly advisable that a definite means be provided which will prevent any looseness between conductor and bearing surfaces o the clamp. While it is advisable to limit the stress upon the conductor or to grade the pressure between conductor and clamp, this becomes more diicult as the grip or pressure is reduced, as looseness and damage due to pounding or vibration tends to increase with light grip in the types of suspension clamp construction heretofore used.

My invention removes or reduces the objections common to clamps of the single or multiple seat type now generally used. These advantages will be particularly evident by consideration of the several gures.

In the form of clamp shown in Figs. l, 2 and 3 the conductor i@ is supported by seat pieces l! which in turn are supported by arms i2. The arms I2 are inverted channel shaped members the side walls or which project beyond the top wall at the adjacent ends of the arms and form ears i2' which are pivotally attached to downwardly extending spaced legs of a socket adapter I3 which transfers the load to the suspension insulator and supporting structure. The arms l2 are U shaped members in cross section hinged by means of the bolts ifi which are used to attach the arms to the socket adapter i3. The bolts M allow the arms l2 to move freely in a vertical plane, the general arrangement being shown in Fig. 3.

Fig. 2 shows section thru the main ciamp seats. The clamp seat li rests in groove formed by turning up the lower edge o the U shaped arm members i2. The clamp seats li may be moved toward the center of the clamp or away from the center so as to change the leverage and pressure between the conductor and seat. The position of the clamp seat with respect to the arm is maintained by a pin l5 or any other convenient means.

It is evident that tension Vin the conductor together with the angle with the horizontal or sag angle will produce a downward force or pressure upon the main seat members i i. Since these seat members are attached to the arms i?. they will tend to throw the outer ends of the arms l2 downward, rotating these arms about the pivot or fulcrum Mi attached to the adapter iember i3. The downward movement or rotation of the arms will 'be arrested by contact between the top walls of the arms at their outer ends and the conductor. The reaction of the conductor on the outer ends of the arms will be suilicient to counteract the tendency of the arms to rotate due to the pressure produced by the bearing oi the conductor upon the seat piece li. The relative pressures between the conductor and the seat pie-ce i i andbetween the conductor and the outer ends oi the clamp will be inversely proportional to the length oi t'ne respective lever arms or distance from the pin or iulcrum i4.

It is readily seen that the pressure upon sea-t pieces Ei will depend upon the weight of the conductor and also upon the angle of sag or angle that the conductor makes with the horizontal and the tension in the conductor. The pressure also will depend upon well 1miown reactions due to the relativedistances from the ulcrum.

As the main seats Il are moved outward from the center or fulcrum thetorque tending to rotate the arms will be increased. This tendency to rotate will be arrested by the pressure between the conductor and the top walls or seats at the outer ends of the arms. Since the rotating torque is increased this can only be counteracted by an increased pressure between the conductor and the clamp at the outer end. t is therefore seen that as the seat piece li is moved outward, the pressure between the clamp and the conductor will be increased. The grip or clamp friction will depend upon the effective coefiicient of friction and the pressure upon the conductor, this pressure being made up of both upward and downward components. if the main seats il are moved inwardly toward the fulcrum the torque tending to rotate the arms i2 will be reduced. The pressure between the conductor IG at the point of entrance also will be reduced.

Since the grip depends upon the pressure and the coefficient of friction which will be relieved by a reduction in tension in the conductor, it is evident that the clamp may be so designed that a broken conductor will tend to relieve the grip and therebylprotect the insulator and supporting structure.

The pressure between conductor and clamp depends upon the tension and angle together with the arm ratio for the clamp seats. This pressure may be controlled within wide limits and there will always be a positive pressure between conductor and clamp seats so that there will be no damage due to a vibrating conductor beating against a clamp. The construction may be very light and the point of contact with the conductor may be well out from the insulator support.

Reference to Fig. l and Fig. 3 shows that the position of the conductor is above the center line of the pin or iulcrum ifi. As the arms move downwardly the location of the conductor will move in the same direction. As the arms move upwardly due to reduced sag the conductor also will move upwardly. As the sag is increased the conductor will move downwardly. It is therefore seen that the position oi the conductor in the adapter i3 may be above cr below the aids oi' the ulcrurn is. It is also seen that the conductor and clamp require but very iittle vertical space. This is of considerable benefit in increasing or conserving tower clearance, which is a very important item of cost in a transmission system.

The general reactions of the clamp just described are shown in Fig. 32, in which figure however the lever arms are pivoted on spaced pivot points ill on a. supporting yoke instead of on a common axis. In Fig. 32 the arm a corresponds to the effective arm for the main seat pieces l! and the arm b corresponds to the effective arm for the reaction seat at or near the outer end of the clamp. The sag angle or angle that the conductor makes with the horizontal is shown by 6.

The effect of changing the arm ratio fL/b, and increasing the clamp friction is shown in Fig. 35.

The eicct of the sag angle in increasing the clamp friction for everal diierent arm ratios is shown in Fig. 3 rEhe `friction in the seat of an ordinary clamp is shown by S in Fig. 36.

The construction permits of a long clamp member without serious inertia effects upon the conductor. The relatively light but denite pressure at the point or" entry of the conductor is a distinct advantage. The long arm also tends to reduce the reaction between the conducto-r and seat at the outer end due to vibration. Since the main arm is free to rotate, any vibration or oscillation in the conductor can readily move the arm with seat pieces so that reflections and bending of the conductor will be materially' reduced. The divided seat pieces II permit of a relatively longer radius of curvature for the conductor than that for a single seat piece.

With the construction shown a very smooth contour of the clamp may be provided as well as arc protection for the conductor without incurring losses or disturbance from corona discharge.

Fig. 4 shows a modification. which is similar to- Fig. 1 except that advantage is taken of the gen-- eral construction in order to provide a frictional system for dampening out vibration. In Fig. 4 the arms f8 and i? are similar to thearms I2 but are provided with extensions I8 and. I9 respectively. These extensions preferably are integral parts of the arms IE5 and I'l, which may be made of pressed metal, forgings or castings.. The outward end of the member I8 is provided with a friction or wearing shoe 26. The frictional shoe bears upon a member 2| attached to the arm I'I. These members are readily replaceable so that they may be made of any suitable material. Projections and locate the friction member on the arm so it will not become displaced. Special attention is given to the design of the pieces so that they may be readily removed and replaced, even where the line is energized, by the use of suitable tools.

The bearing pressure and friction is increased by a spring 24 which bears upon the arm extension I8. The friction surface and 2I may be dispensed with where ample material is provided in the clamp so that wear will not cause a serious weakening or where the danger of vibration is very small.

The pressure upon the frictional surfaces may be increased or reduced by adjusting the nut 25. A rib Washer 26 is provided so that the nut cannot become loose. The main seat pieces 21 are supported by pins 26. A seat piece 29 extends thru the main seats 2'5, bridging the space between them and distributes the curvature in the conductor preventing sharp bends where the conductor leaves the seats of the clamp even though the seats have rather smail longitudinal length. The location of this seat piece is shown in Fig. 6. The distributing member 9 may be made up of one or more members of any convenient form and may be used with practically any of the designs.

The arms I6 and l "l are provided at their outer ends with clamping means which increase the grip on the cable over that normally provided by the reaction between conductor and clamp. The stirrup 3u slips over the arm I6. A clamping piece 3! is forced against the conductor I0 by means of a screw 32 operating in a yoke member 33 which engages the stirrup 30. It is readily seen that a grip means of this kind may be added or removed from the clamp at any time to provide for a change in conditions.

The grip produced by the clamping member at the end of the arm supplements the grip due to the clamp reaction, therefore the loosening of this member would not necessarily cause destruction of the conductor. The member is so designed that should it become loose it will drop iree of the clamp and conductor and not remain in position to hammer the conductor.

Fig. 8 shows a somewhat different modification in which a compound arm 34 is used in order to increase the clamp friction materially. The arm consists of a member 34 hinged at 35 to a seat member 36. The upward pressure on the member 34 due to the conductor reaction tends to throw the inner end of the member 34 downward. This bears upon the -pins 31 which in turn press upon the grip members 38, thereby increasing the pressure between the main seat members 36 and the conductor. The friction is also further increased by the pressure between the seat 38 and the conductor. It is readily seen that this makes it possible to materially increase the pressure upon the conductor. 'I'he arms 34 may be placed either inside or outside of the U shaped seat pieces 36.

As shown in Fig. 9 the arm 34 bears against the pin 31 which in turn bears upon the seat piece 38. Clearance space 39 is provided so that the seat piece may be forced against the conductor I0. is shown for extending the seat and increasing the effective radius of curvature. It is evident that this member may be placed inside the main seat pieces or be used as a supplementary extension. These pieces are threaded thru an eye 4I formed in the regular seat piece.

As shown in Fig. 10 the main parts of the clamp are readily made from pressed metal parts, and therefore can be very light. By placing the fulcrum or hinge point 42 suiciently low the tenf dency for the conductor to slide in the main clamp seats with the change in sag angle will be negligible. This avoids any tendency of chang due to slipping of the conductor ln the clamp seat, due to change in sag angle from vibration or tension in the conductor.

In the modification shown in Figs. l1, 12, 13, and 14 the clamp produces a horizontal bend in the conductor as it passes thru the clamp to 1nsure a good contact between conductor and clamp seats and also to provide a pressure for the vibration dampener system. The arm 43 is provided with a main seat 44 open at its top and a downwardly opening seat 45 at the end of the arm. 'Ihe arm 43 has an extension 43 which is equipped with a friction pad 46. The arm 41 is similar to 43 except that its extension 4l is carried by a bushing 41" which passes thru a hole in the arm 43.

The socket adapter 5I is placed approximately in line with the portions of the conductor as they enter the clamp. This prevents tipping of the clamp or rotation about a horizontal axis. In general slight deflection only of the cable is necessary to produce the necessary dampening ,I

friction. However, if it is desired to change the deflection and frictional forces the arms 43' and 41 may be bent inwardly or the thickness of the friction pads 46 increased. This will increase the deflection and pressure. The pressure and friction losses may be reduced using thinner friction pads 46 or bending the arms 43 and 41 outwardly.

The general arrangement of the parts and the method of producing pressure for dampening vibration and for increasing grip in the clamps is shown more clearly in the plan shown in Figure 12. The tension in the conductor tends to straighten out the conductor as it passes thru the clamp. This tends to make the main arms with the friction members rotate so that the friction member attached to one arm tends to bear against the complementary arm on the opposite side of the fulerum or axis. It is readily seen that the pressure may be changed material- The supplementary spring piece 40 f (ifi ly by changing the horizontal offset in the conductor. The arms :i3 and 4'l are prevented from moving longitudinally by the pin llt-the arrangement being shown more clearly in Fig. 14. The pin works in slots in projections from the main arms 43 and 4l. This prevents the rotation of the seat pieces about a horizontal axis. These slots allow a horizontal rotation of the arms with respect to ca-ch other about the bearing on pin 48. It is evident that a horizontal rotation will be arrested by the pressure between the arms 43 and 4l upon the main clamp arms. Any change in the angle of sag due to vibrations or oscillations will cause the arms fit and 4i" to move with respect to the main bodies, This will cause the friction losses between the friction members 46 and the main clamp body or arms. In order to provide a wide working range for sag angle or rotation about the fulcrurn, the clamp ybody is provided with projections *it so that the friction pads 46 will have a bearing surface thru the working range. The friction pad 46 is used to control the coecient of friction and may be readily replaced should excessive wear take place. The main body of the clamp may be provided with a wearing shoe as previously described or the surface made sufliciently thick so that wear will be provided for.

The socket adapter 5l is part of a rigid member or arm to which the pins 48 and 4S are at tached. The arm 52 passes underneath the clamp seats and conductor and provides an open seat so that the conductor may be dropped into place. This arrangement permits the assembly of the clamp before placing the conductor in position. However, it is evident that the socket adapter may be provided with an inverted U similar to that shown in Figure 10 to which the pins 48 and 49 may be attachee. However, this will complicate the assembly in attaching to the conductor.

Fig. 15 shows another modification of the clamp in vwhich the arm ratio may be readily changed in order that the grip or friction may be con- Ytrolled. Where the clamp friction cr grip can be controlled strong towers may be occasionally with lighter intermediate towers. Ey increasing the clamp grip or friction at the strong towers any tendency for a successive tower fail ure or cascade will be arrested by the strong towers. This will permit the use of light and less expensive towers for the intermediate struc tures particularly where the grip or stress placed upon these intermediate towers is limited by the grip in the clamp. Increasing the arm ratio will make it possible to increase the grip very materially. In addition clamping means may provided for the main clamp seats.

Such an arrangement is shown in Fig. The main arms are made of two parts and 55.'. The arrangement of the parts is shown more clearligT in Fig. 16. The member 53 is a L! shaped member with an upturned edge which provides a seat for the U shaped member iid. In order to change the arm ratio the pin may be removed and the seat member 5l shifted to a new location and the pin inserted in another hole. The arm ratio also may be changed by sliding the arm 54 in or out with respect to the complemenv tary member 53, the pin 56 when reinserted maintaining the relation between the two members. The clamp or seat piece 5i is carried by the pin 55. This clamp may be made in any desired form and is shown provided with clamping sc ews or bolts 5S which are used to increase the friction.

Seat pieces 59 working: in straps attached to pins il provide seats at the outer ends of the clamp. This arrangement permits of longitudinal movement of the conductor with respect to the clamp arm without slippage between the conductor and cooperating clamp member. The arms are attached to yole 52E by means of links The yoke in turn is attached to the insulator or support by a link or adapter ed.

The links @E permit of longitudinal movement of the main clamp seats or arms to provide for changes in sag angle without the conductor slipping in the clamp seats or producing a serious bend.

In Fig. 17 a single main seat piece is used in place of multiple seat pieces. The seat piece 65 is supported from two arms tit by links li. The arms are inverted U shape in cross section. The attachment of the links more clearly shown in Fig. 20. It is evident that the links tl permit of a free rotation of the arms tt about the fuln crum t8. The links 6'! bear upon the arm p1. 66, tending to force the outer ends downward. This is resisted by the reaction between the conductor and clamp seats E59, the principle being the same as that in the forms of clamps previously described. With this arrangement there he some longitudinal movement betweiin the ce iductor and the outer ends of the clamp. This might cause destruction of the conductor and clamp. To prevent damage a seat piece provided which is free to move in the general direction of the arm or axis of the conductor as shown more clearly in Fig. 19.

The pin 'iii projects thru an elongated hole in the arm GS which permits the necessary movement. A head is provided for this pin so t the seat piece 6g will not become diseng before or during assembly. Friction plates 'i i are placed between the seat piece and the arm Gi. These pieces control the friction and remove wear from the main clamp members. It is evident that any longitudinal movement due to a change in the angle taken by the arm will cause dissipation of energy due to friction losses. Th will tend to dampen out vibrations. The relative movement may be materially increased by ing the point of rotation 68 well above the axis of the conductor.

A modified form of seat which may be used in place of the seat 59 which provides for longitudinal movement dampening at the point of entry of the conductor to the clamp is shown in Fig. 21. The seat piece 53d is carried by a pin 'Fd' operating in elongated holes in the side walls of the arm t6. The pin in is supported by links which permit longitudinal movement of the seat et with respect to the arm G5 so that the conductor will not slip over the seat piece tt. The longitudinal movement of the .seat S9 causes movement of a spring member 'Si' attached to the seat. The member Tl moves an arc about the center of rotation of the supporting links. It is evident that the longitudinal movement of the member l relative to the arm on which it bears, is greater than that between the conductor and arm 65. This increase in the movement of the friction dampening members is very beneficial as the forces and wear between parts may be decreased and the dissipation of energy for slight vibration materially increased. The dampening member 'il' is shown as a spring which is readily slipped into place, being held in Fig. 25.

by a pin. The friction member 1|' is not concealed and hence more readily inspected for Wear than the friction members 1|.

In the modification shown in Fig. 22 the arms 12 rotate about a pin 13. The main seat pieces 14 are attached to the arms by links 15, and pins 16. The arrangement is more clearly shown in Fig. 24. The link 15 is provided with tongues 'i1 which are pressed inward so that the clamp seats 14 cannot become disengaged from the link or stirrup 15 which permits rocking or longitudinal movement. Spaced holes may be provided in the arm 12 for the pin 16 so that the arm ratio and clamp friction may be adjusted by shifting the pins 16 and seat pieces 14. Longitudinal movement at the end of the clamp is provided for by a seat piece 18 which is free to move with respect to the arm 12, the arrangement of part-s being more clearly shown in Fig. 23. The seat piece 18 bears upon a pin 19 which in turn bears upon the under surface of the arm 12. The pin 19 moves in a slot 80 in the arm. The seat piece 18 is provided with a rib 8| which prevents it from becoming disengaged from the arm before or during assembly. The arrangement in Fig. 22 permits of a material rotation of the arms 12 about the fulcrum 13 without producing slipping between the conductor and clamp members.

Since clamps of this construction would produce little friction due to movement and consequently small tendency to dampen out vibrations or oscillations, it may be necessary to provide dampeners. One form of such a dampener is shown attached to one of the arms in Fig. 22. The construction of this dampener is more clearly shown The dampener case 82 is provided with a cover 83 and is .attached to the clamp arm by a spring member 84, which is attached to trunnions or pins 85. The dampener case encloses a piston 86. This piston has appreciable mass .and therefore tends to remain stationary as the case is moved up and down rapidly due to vibration. The case preferably is lled with oil, glycerine or some fluid which will tend to resist the movement of the plunger 86 and dissipate energy as it ows past or thru the plunger.

In order to reduce wear the plunger is so designed that it will tend to rise or oat so that there will be little or no contact and wear between metal parts. To accomplish this valves 81 and 88 are provided. These valves permit of a free downward iiow of the fluid thru ports but resist an upward flow. This tends to support the piston 86 until sufficient ow takes place thru openings or around the outside of the piston. By making this piston conical and the inside surface of the case to correspond, it is evident that freer passage will be provided for the fluid as the piston rises. With this arrangement it is seen that the piston will tend to float free of either end. Springs 89 and 99 are provided so as to prevent damage during installation or for occasional severe movements in the arm which might cause a battering between the piston and case.

Two arrangements of valves are shown-an ordinary common plate or feather valve construction being shown in 81, and .a sleeve valve 88 worked by inertia. It is evident that the axis of the piston should be normal to the movement of the arm. For this reason there may be a tendency for the piston to rub on the side of the case. This may be prevented by providing longitudinal grooves and a larger space 9| between the case and piston on the low side. This Will provide a more effective pressure on this side and tend to force the piston in the opposite direction. This space preferably is provided in the proper side of the case so that the piston may be conical and free to rotate. This space generally would be rotated 90o from that shown 1n Fig. 25.

In the form of the invention shown in Fig. 26 the yoke S2 is provided with pins 93 to which arms 9d are attached. The arms 94 are attached to seat pieces 95 by means of pins 9G. The arm 94 bears on the conductor at its outer end 94. The seat piece 95 extends inwardly well past the pin 93. It is evident that if the arm 84 and the seat piece 95 were integral the bearing between the conductor .and seat piece 95 would be the same as if the seat piece 95 were attached to the pin 93 by ears fixed to the seat piece. Therefore the position of the seat piece 95 would be the same as if it were supported by the pin 93, the arm 94 although hinged at 98 is held against rotation with respect to the seat piece 95 by contact with the cable. Any downward pressure produced by the cable upon the seat piece 95 will tend to cause the pin 95 to rotate about the pin 93. This will tend to force the outer end 94 downward against the conductor. Rotation of the seat piece 85 about 9S will be resisted by the force on the inner end so that the pressure between the conductor and the seat piece 95 and the seat piece Sii will depend upon the eiective lever arms and the tension and sag angle of the conductor.

Provision for longitudinal movement without slipping of the conductor is provided with slots 91 cr by attaching to the yoke by means of links as shown in l5. It is evident that the clamp seats may be reversed in direction, Ithe gripping portion instead of being placed outwardly being placed adjacent to each other' as shown in Fig. 37. It is also evident that these may be placed in the same general direction or if desired a single member only need be used. This will permit of a greater grip in one direction than in the other in case of a broken conductor if so desired. It is also evident that a single seat piece with two clamping arms may be used if de-.

sired, the clamping arms being attached by separate pins to a yoke member er to a common pin.

Fig. shows a modified form of reaction type of clamp in which the pins for attaching the seat pieces are placed at one side of the conductor. This permits of one or the mest inexpensive and simplest types oi construction. The arms 98 are attached to the yoke S9 by pins |66. Slots |0| are provided the arms so as to permit change in the sag angle without slipping or bending of the conductor. Slots and holes are provided in yie arms 98 so that ratio may be changed. This type of construction permits of a large part or the clamp being made up of light pressed metal parts in order to provide light weight and low cost. An arrangement of the parts is shown in Fig. 3i.

The clamps are particularly applicable to hollow or light conductors which may be made up of segments, tubular members or members made up in various shapes. The clamps are also adaptable to other types of conductors in which favorable conditions are desired in order that high working tensions may be used .and improved conditions for vibration provided. Aluminum conductors having steel cores or conductors having high strength cores. lower strength outer layers which are likely to be damaged by bending or friction are readily supported by clamps of the type shown.

, el .ro snrxeg snc Fig. 32 is a diagram showing the general relachanging the arin ratio. Referring to Fig. 35 tions of pressure between the clamp members and R shows the increase in grip or clamp friction Conductor, due to a change in tire arm ratio as compared l il The general principles are the same w e er o ie grip pro dees. ey a c lds@ `i-, ..0 or not the aims are attached to a common point single seat without clamping rnernbers. 5 of rotation or to two spaced points on a yoke as Fig. 36 shows the effect of the sag angle upon in Fig. 32. In Fig. 32 the tension T in the conclamp friction for several diierent arrn ratios ductor acting thru the sag angle produces a total and S for a single seat clamp. It is readily downward pull upon the clamp system which seen that the invention maires it 'possible to ccn- 10 must be resisted by a counter force L. In Fig. struct a clamp which will have long arms and 10 32 the force exerted by the main seats upon the provide a large radius or" curvature for the conconductor is shown in magnitude and direction ductor without producing excessive bending by M and that of the reaction clamps at the moments as would be the case where cla-inps of outer ends of the arm by N, The effective arrn the ordinary type are used.

l5 lengths tending to cause rotation of the arms The automatic adjustment or the clamp for 15 are Shown by a and b. changes in sag is or very great benefit as it is understood that in the diagrams the it is not necessary to change the grip members. .forces are the Same on either side of the center The construction also permits of gripping the line. In the case of `an unbalanced force the tenconductor due to reactions set up by tension in sion in the conductor will be diferent on the two same. 20 sides. However, reference to Figs. and 36 will The construction also permits of a vertical show that the clamps may be designed for a very movement in the conductor, reducing reflections. large unbalanced force or so as to liinit the grip The invention also adapts itself readily to cla-.np and the amount of the unbalanced force. members which will provide arc protection and 25 The analysis of the resultant forces is more darnpener schemes which will absorb or limit the 25 clearly shown in Fig. 33 where the main resultamplitude of vibration. ants of the force exerted upon the clamp by the` The point of rotation -may be placed any Conductor and insulator or support only are desired point above or below the conductor, makshown. The angle c plus angle e equals 180, ing it possible to select a position which will 30 3o cause a negligible longitudinal movement beor C+{18O-HH-18O tween the conductor and the clamp members or all quantities being eXDressed in degrees. arms for a considerable change in angle of sag. Also d gzc or dzc+0 The construction permits of manufacture at relatively low cost for clamps of large size and 55 Since the arms of the Clamp Will rOtae until the f such contour corona or brush discharges 35 forces are balanced, the resultant M acting on will be avoided the main seat thru the arm a Will be balalCe-d The arrangement is such that a broken conby the force N acting upon the TeaC'On Seal ductor will not produce serious bending moments thru the arm b. The resultants M and N upon the clamp and the multiple seats reduce the lo will bisect the angles c and d ISSpGCtViY, radius of bend in case or" a broken conductor. 40 therefore Ready means are provided ier controlling the M a=N Xb grip so 'that strong and light towers may be used However, assuming that the tension in the conto gffeatesf awmageductor is the same .at all points the resultant Flg' 37 1S 511mm? t@ F39 with the exception 40 forces Mu and Nn Wm depend upon the. angle that the conductor seats have been turned around 4') ucl, and ndi, or with respect to the yoke. This reduces the length of conductor between grit` points so that any M =2 T 00S (f3/2) tendency of the conductor to buckle or bend due and to a change in the sag angle would be reduced N=2T COS (l1/2.) materially owing tc the short section of conduc- 50 The torques produced by M and "Ni, mugt be tor between the clamp pieces. It is evident that the two main body pieces can be combined. Howedual and ODDOSIG, 01 MW. i Mmmm1 wm-s i@ M+ grim-saws imlpqq Hw liti" e t inal e to p a l W W us'which tennstd'reduc'r or brush discharges. The outer ends of the clamp are equipped with large rounded terminal portions l2l. By providing these with a slot or opening S22 the sides may pass down over the conductor and produce screening without coming in contact with the conductor.

The yokes H5 permit the ready adjustment or equalizing of force upon seat pieces H6 on either side of the yokes. The two seat pieces and a yoke act similar to a single main seat piece. However, the use of two seats in place of one makes it possible to utilize the contact surface of the seat pieces over a much wider range of curvature, and the conductor can be supported with minimum amount of bend over a much pieces further be unifo of the se dependir.

ductor a the seat: ,-J une curvature bearing will take place near the outer ends so that the conductor may be regarded as supported at a number of spaced points. The length of seat may be so taken that these points will supply a uniformly distributed support for the conductor as it passes thru the clamp.

As the sag angle increases the arms swing downward. The pins H8 with the yokes H5 and clamp seats H6 tend to move inward and downward. It is evident that the radius of curvature for the conductor also will be decreased, as the maximum radius which may be obtained for a uniform bend will be normal to the resulting force passing thru the pins H8. As the points i lll move inward the chord for the arc formed by the conductor will be decreased. However, if the radius for a given chord is decreased suiciently the same length of arc will be required for the reduced length of chord. By selecting the proper distance Y and the proper height of the hinge point H4 with respect to the seat pieces n the arms H2 a relation may be obtained so that the arms may swing thru a very appreciable angle without any tendency on the part of the conductor to slide in the seat pieces.

With the lever type of clamp it is possible to move the hinge points fer the arms either up or down with respect to the location of the conductor. This is a. material advantage as will be seen by a consideration ci Fig. 4l.. In Fig. 41 the arm swings about a hinge point K. e is the distance to the main seat or resultant M of Figs. 33 and 34. H is the distance between the tangent to the center line of the conductor and intersection with M and a, which is normal to the resultant M, This permits the determination of the radius of curvature for the conductor and the length of an arc of uniform radius r different values of the angle X. s of curvature will will R=H+11H|a @Otan X tui length of arc between the two main seats Since the angle X will vary with the angle of sag all that is necessary to determine the proper value for H for a given value of d is to substitute diierent values of I for the working range of the angle r, and determine the length of arc. The length of are should be approximately constant thru the working range of 0 in order to avoid slipping. This simplifies the construction oI" the clamp, reducing the number of parts and eliminates the necessity of links or slots.

Where the working range of sag angles is small "H usually will be less than For larger sag angles this va 1' no n the angle of the arm angle therefore it is possible to change the value of as the ratio oi the length of the arm a to the distance from the center line to the hinge point of the arm Y is decreased, the value of 1. must be decreased and becomes negative in the equation when placed above the line of tangency. By Ychoosing the proper relations of yoke length, arm length and the value of H a wide variety of com inations may be made up in which there will be little or no tendency for the conductor to slip due to a change in the sag angle when a uniform radius o1 curvature is obtained. The uniform radius of curvature may be approximated very closely by providing sufficient support, by the seats, increasing the number of seats, or by using a supplementary support where u .l be readily determined once "R is known. lhe length of arc between the tivo main resultthe rigidity of the conductor will not provide the proper arc between bearing points or seats.

It is evident that as the radius of curvature increases there will be a tendencyfor the conductor to slip between seat pieces attached to the same yoke unless the clamp seats move so as to shorten the chord for the conductor between these two seats so as to conform to the changed radius of curvature. This is readily provided by raising the trunnic-ns or point of pivoting of the seat pieces above the center line of the conductor. This distance is generally from four to six percent of the distance between the hinge points of the yoke. This method of changing the length of chord to compensate for the change in radius is shown in my copending application Serial No. 700,271, filed November 29, 1933, which has now become Patent No. 2,062,283, December l, 1936.

I claim:

l. A support for a conductor comprising a pair of arms pivotally supported at their adjacent ends, a seat on each arm for supporting a conductor, said seats being spaced from the pivotally supported ends of said arms so that force exerted by said conductor upon said seats tends to swing said arms toward each other about said pivotal support, and a stop on each arm for engaging said conductor to limit the pivotal movement oi said arm and to cooperate with said seat to grip said conductor.

2. A support for a conductor comprising a pair of arms pivotally mounted at adjacent ends thereof, each arm having a seat thereon spaced from its pivotal support for engaging a conductor, a stop on each arm for engaging said conductor at 4points spaced from said support beyond said seats to limit rotation of said arms under the force exerted cn said seats by said conductor and to cooperate with said seats to grip said conductor, said stops being held in contact with said conductor for various angular positions thereof relative to said support, and frictional means for damping out movement of said arms about their pivotal support.

3. A conductor support comprising a carrier member, arms having spaced ears pivotally mounted on said carrier member and providing clearance for movement of a conductor vertically past the pivotal axis of said arms, a seat for a conductor carried by each of said arms at points spaced from the pivotal support therefor and stops carried by said arms for engaging said conductor to grip the conductor and to limit rotation of said arms about their pivotal support.

4. A support for a conductor comprising a pair of pivotally connected arms, each arm having an extension thereon, projecting past its pivotal support and having irictional engagement with the other arm to damp out relative pivotal movement of said arms, and means on said arms actuated by the force exerted thereon by said conductor for gripping said conductor.

5. A support for a conductor comprising an arm formed of pressed metal and having an inverted U shape in cross section, the edges of said metal being bent inwardly to form grooves, a seat supported in said grooves and adjustable longitudinally of said arm and means for holding said seat in its adjusted positions.

6. A support for a conductor comprising a gripping member pivotally mounted at one end thereof and engaging a conductor adjacent the opposite end thereof, said gripping member extending longitudinally of said conductor so that its ends are spaced apart in the direction of the length of said conductor and a seat member pivotally mounted on said gripping member at a point spaced longitudinally of said gripping member between the point of pivotal mounting of said gripping member andk said point of engagement ci said gripping member adjacent its end with said conductor, said seat member engaging the side of the said conductor opposite that engaged by said gripping member.

7. A conductor support comprising a pair of arms pivotally mounted at their adjacent ends, a seat member carried by each of said arms for supporting a conductor, a contact member carried by each arm and cooperating with the seat member thereon for limiting the rotation of the arm and for gripping the conductor, and means for frictionally engaging a friction surface xed to one of said arms for damping vibrations in said conductor.

8. A support for a conductor comprising a pair of arms pivotally supported at their adjacent ends, a seat on each arm for supporting a conductor, said seats being spaced from the pivotally supported ends of said arms so that force exerted by said conductor upon said seats tends to swing said arms toward each other about said pivotal support, and a stop on each arm spaced longitudinally of said arm away from the pivotal support beyond said seat, for engaging said conductor to limit the pivotal movement of said arm and to cooperate with said seat to grip said conductor.

9. A conductor support comprising a lever arm, a fulcrum support for said lever arm, a seat for a conductor carried by said lever arm and spaced away from said ulcrum support so that pressure on said seat tends to rotate said lever arm about its iulcrum, a stop on said lever arm in position to engage said conductor at a point along said arm beyond said seat from said fulcrum and at the opposite side of said conductor from said seat, to limit the rotation of said lever arm about its fulcrum and to cooperate with said seat to grip said conductor.

l0, A support for a conductor comprising a pair of lever arms pivotally supported at adjacent ends, a seat on each arm for supporting a conductor, said seats being spaced from the pivotally supported ends of the arms so that force exerted by said conductor upon said seats tends to swing said arms toward each other about their pivotal supports and 4a stop on each arm spaced from its pivotal support beyond the seat thereon for limiting the rotation of said arm about its pivotal support and for cooperating with said seat to grip said conductor, said stop being movable on said arm to provide for relative movement between said arm and conductor without slipping between said conductor and stop.

11. A support for a conductor comprising a pair of lever arms pivotally supported at adjacent ends, a seat on each arm for supporting a conductor, said seats being spaced from the pivotally supported ends of said arms so that force exerted on said seats by said conductor tends to rotate said arms about their pivotal supports, and a stop on each arm for engaging said conductor to limit the pivotal movement of said arm and to cooperate with said seat to grip the conductor said seat being movable on said arm to provide for relative movement between said arm and conductor without slipping between said conductor and seat.

l2. A support for a conductor comprising a pair or" arms, means for pivotally supporting said having a frictional surface xed thereto and engaging a frictional surface fixed to the other of said arms to damp out vibrations imparted to said arms by said conductor.

ARTHUR O. AUSTIN. 

